A Buckinghamshire Fire and Rescue Service spokesman said it was too early to give a cause but "what's burning is very combustible and dry" due to the weather and that they would likely be battling the blaze through the night.

You must enable JavaScript to view this content.

Compare the temperature where you are with more than 50 cities around the world, including some of the hottest and coldest inhabited places. Enter your location or postcode in the search box to see your result.

Find a location

Your location

°C

°C

°C

Forecasters say high pressure will continue across much of Britain throughout the next two weeks, "bringing plenty more very warm sunshine".

Provisional figures show the highest temperature on Monday was 30.7C recorded at Bournemouth Airport.

BBC forecaster Gemma Plumb said England and Wales saw temperatures of between 25C and 29C while Scotland and Northern Ireland reached between 20C and 24C.

"Tomorrow will be much more of the same although with more cloud for the north and east of Scotland," she said.

Media playback is unsupported on your device

Media captionEnvironment Agency rescues more than 130 trout and salmon from River Teme

Eastern coastal areas may also see more mist while showers are a possibility in the Channel Islands and southwest England.

Pollen levels will be high or very high across most of the country, although they will be slightly less in areas with cloud.

Ms Plumb said: "It's going to be dry, fine warm weather into at least next week."

But the UK still has a way to beat the record of the 1976 heatwave, which saw temperatures of 32C and over for 15 consecutive days.

'Use water wisely'

Southern Water, which supplies water to parts of Kent, Sussex, Hampshire and the Isle of Wight, said it was asking customers to help "keep taps flowing across our region".

It said it had boosted its supply this week by an extra 87 million litres of water a day compared with a week ago.

"We are not in drought restrictions but we are asking customers to use water wisely in the garden and avoid washing cars and windows until it begins to cool down."

United Utilities, which operates in the north-west of England, said it has seen a "massive increase in water consumption across our area" and it was "struggling to get enough water around the system quick enough".

"Yesterday an additional half a billion litres was used and it has been the same today," the company said on Friday.

"We urgently need your help and support to avoid a hosepipe ban. You can help us by turning off your garden sprinklers, not using your hosepipes, not washing your car and taking shorter showers and not baths this weekend."